Blast furnace distributor seal



Oct. 13, 1959 ARMOUR 2,908,407

BLAST FURNACE DISTRIBUTOR SEAL I Filed March 15, 1956 5 Sheets-Sheet l I INVENTOR.

- FR NK K. ARMOUR BY f OMQ 3 6.44/

AT RNE/S Oct. 13, 1959 F. K. ARMQJR 2,908,407

B LAST FURNACE DISTRIBUTOR SEAL Filed Mar ch 15, 1956 5 Sheets-Sheet 2 V INVENTOR. FRANK K. ARMOUR BY A rromvsys zgfi T ll 3544/ F. K. ARMOUR 2,908,407

BLAST FURNACE DISTRIBUTOR SEAL Oct. 13,. 1959 Filed-M01115, 1956 s Sheets-Sheet :s

INVEN TOR.

FRANK K. ARMOUR BY ATToR NE 75 0a. 13, 1959 F. K ARMCSUR 2,90

BLAST FURNACE DISTRIBUTOR SEAL Filed March 15, 1956 5 Sheets-Sheet 4 i 42 ,1 g 2 'i w l 1 z 36 a .Elg- 5 INVENTOR.

FRANK K. Anmoun BY EW fflagew Arrow/E Oct. 13, 1959 Filed March 15, 1956 F K. ARMOUR BLAST FURNACE DISTRIBUTOR SEAL 5 Sheets-Sheet 5 INVEN TOR.

FRANK K. ARMOUR BY .MPMAI MAW United State 2,908,407 BLAST FURNACE DISTRIBUTOR SEAL Application March 15, 19%, Serial No. 571,760 10 Claims. (Cl. 214-37) This invention relates to blast furnaces generally and more particularly relates to an improved seal for a blast furnace distributor.

A typical :blast furnace to which the improved seal of this invention is applied utilizes a vertically disposed furnace shaft having a distributor in the form of a revolving bell and hopper extending downwardly into the top of the furnace shaft. The improved seal prevents the escape of dust-laden furnace gases through the annular space between the distributor and the top of the furnace shaft. Heretofore, various types of packing have been utilized in the annular space between the distributor and the top of the furnace shaft but, because of the relative movement between the distributor and the furnace shaft, the packing has been subject to excessive wear and maintenance which reduced its effectiveness.

Accordingly it is a principal object of this invention to provide a more effective seal between a distributor and the blast furnace shaft which is relatively free of friction and subject to a minimum of wear and maintenance.

Briefly, in one form of this invention, the improved seal is accomplished by providing annular grooves disposed in registered relation opposite each other respectively in one surface of the distributor hopper wall and in the adjacent wall surface of the furnace shaft and by seating a ring of sealing material in the area defined by those grooves to block the gas escape path. In its preferred form, the gas escape path between the distributor hopper and the top of the furnace shaft follows a structurally' formed labyrinth or sinuous path, one end of which is exposed to the interior of the furnace shaft and the other end of which is sealed by one or more sealing rings seated in the opposed grooves. A suitable lubricating and cleansing fluid such as grease is introduced adjacent the sealing rings and into the labyrinth path on the furnace side of the sealing rings so that the furnace gas will act directly on the column of fluid instead of the sealing rings.

In the drawings:

Fig. 1 illustrates in cross section the charging portion and the distributor at the top of the blast furnace;

Fig. 2 is an enlarged sectional view showing a portion of the improved seal in greater detail;

Fig. 3 is a sectional plan view of the distributor taken along the line 3-3 in Fig. 1 of the drawings showing its segmental wall construction;

Fig. 4 is a top plan view of an annular skirt carried by the distributor hopper;

Fig. 5 is a sectional view taken along the lines 5-5 in Fig. 4 of the drawings;

Fig. 6 is a top plan view of a segmental spider portion of the distributor which forms the outer wall for the sealing chamber;

Fig. 7 is a sectional view taken along the lines 7-7 in Fig. 6 of the drawings;

Fig. 8 is a fragmentary, perspective view showing sepafated' mating extremities of the segmental sealing rings;

and

* tet Fig. 9 is a fragmentary edge view showing the ends of the segmental ring sections of Fig. 8 assembled in interfitting relation.

Referring now more particularly to Fig. 1 of the drawings, the top of the blast furnace shaft is formed by a large bell chamber 10 which is open at the top to receive a distributor hopper 12 into which a skip car or other loading device may dump its charge in a manner well known in the art. The distributor hopper 12 is in the form of a vertically disposed cylindrical chute open at the top and bottom with the bottom being closed by a vertically reciprocable small bell 14. In practice, the small bell 14 is carried at the lower end of a tube 15 through which a suitable bell rod may pass for supporting a large bell closure in the large bell chamber 10. It is customary to provide suitable hoisting mechanism for lowering the small bell 14 to open the hopper 12 and for raising the large bell to drop the charge into the interior of the furnace.

To provide for uniform distribution of the charge, the hopper 12 is rotatably supported in the open end of the large bell chamber 10 by providing it with an annular flange 17 which carries upper and lower tracks 18 and 19. These tracks are guided respectively by upper holddown rollers 20 and lower supporting rollers 12, each of which is journaled in bearings mounted on suitable strutlike members23 which form part of the bell chamber frame. The flange 17 also carries a ring gear 25 at its periphery which meshes with a pinion 26 keyed on the upper end of a spindle 27 which is journaled in a suitable bearing 28 on the frame of the large bell chamber 10. The spindle 27 also carries a pinion gear 29 at its lower end which engages a power driven worm shaft 30. The shaft 30 may be driven by a suitable mill motor not forming part of this invention and therefore not shown.

The upper portion of the bell chamber frame also supports a spider 32 in the form of a segmental annular wall which is spaced radially from and forms an annular trough 33 with a vertically extending wall portion 34 of the bell chamber frame. In order to provide a labyrinth escape path for the dust-laden furnace gas from the interior of the bell chamber 10, a segmental annular sleeve 35 is carried by the annular hopper flange 17 in radially spaced relation from the hopper 12. The sleeve 35 depends downwardly to provide a main skirt 36 that extends into the annular trough 33 formed at the top of the bell chamber frame. The sleeve 35' also has a secondary skirt portion 37 spaced radially inward from the main skirt 36' and depending downwardly from a point intermediate the top and bottom edges of the sleeve. The main and secondary skirt portions 36 and 37 define an inverted annular trough 38 which accommodates the vertically extending wall portion 34 of the bell chamber frame. As a result, in this form of the invention, the furnace gas is required to pass upwardly between the vertically extending wall portion 34 and the secondary skirt 37, thence downwardly and around the main skirt 36 and upwardly between the sleeve 35 and the spider 32.

Referring now more particularly to Fig. 1 in conjunction with Fig. 2 of the drawings, there is shown an improved arrangement for sealing the gas escape path from the atmosphere. This seal takes the form of one or more annular sealing rings 40 spaced from each other axially along that portion of the gas escape path defined by the sleeve 35 and the spider 32. Each sealing ring 40 is supported in registered opposed grooves or recesses formed respectively in a relatively stationary part of the furnace 1'0 and a relatively movable part of the hopper 12. In the form illustrated, one groove 41 for each ring is formed in the inner wall of the spider 32 and a coacting groove 42 is formed in the outer wall of the sleeve 35, The opposed grooves form an annular seat for each sealing ring and coact therewith to provide a satisfactory seal for the gas escape path. Each sealing ring comprises a flexible, resilient, preferably rubber-like material, such as neoprene, and each ring extends across the gap between the furnacewall and the distributor, and substantially fills each portion of the associated coacting grooves.

In a preferred form shown in Figs. 1 and 2 of the drawings, two sets of three sealing ring-s each are disposed on opposite sides of a chamber formed by an annular groove 43 in the outer wall surface of the sleeve 35 This chamber is in communication with a conduit 44 extending through the spider wall. Another conduit 45 communicates through the bottom of the spider wall with that portion of the gas escape path on the furnace side of the sealing rings. A suitable lubricating and cleansing agent, such as grease or other fluid, is introduced through each of the conduits 44 and 45. The fluid introduced at the upper conduit 44 acts as a lubricant for the sealing rings 40 and the fluid introduced through the lower conduit 45 acts primarily as a cleansing agent for the dustladen gas and serves as a fluid column against which the gas may act, thereby preventing direct contact of the gas with the sealing rings.

It will be readily apparent that the greater the gas pressure exerted on the sealing rings 40 the tighter the seals become, because the sealing rings are free to move upward against the upper horizontal surfaces of the grooves 41 and 42 which act as a seat against which the rings seal. Such increased gas pressure would be present during operation of the large bell when the bell 14 would normally be closed. After operation of the large bell, the sealing rings 40 would move downward slightly from their raised position and assume their normal position within the supporting grooves 41 and 42. In the lower position of the rings 40, as well as in the raised position, the friction thereon is negligible, as compared to any friction type seal and, as a result, resistance to rotation of the hopper and wear on the sealing rings is reduced to a minimum.

In the preferred form, the spider 32 is assembled from segmental annular Wall sections such as 32(a) shown in Figs. 3, 6 and 7 which may be connected together in end to end gas tight relation to permit any individual selected portion to be removed for inspection, maintenance, or replacement of the corresponding sealing ring segment. This segmental construction of the sealing rings 40 is best shown in Figs. 8 and 9 of the drawings 'where opposite ends of each sealing ring segment are shown notched at 46 to provide an interfitting halving joint between mating ends for assembly within the annular grooves 41 and 42 in the manner hereinbefore described.

I have shown and described what I consider to be the preferred embodiment of my invention along with modified forms and suggestions, and it will be obvious to those skilled in the art that other changes may be made without departing from the scope of my invention as defined by the appended claims.

I claim:

1. A seal for preventing the escape of gas from between the top of a blast furnnace and a distributor rotatably supported therein in horizontally spaced relation thereto to provide a clearance gap therebetween comprising, means forming a restricted gas escape path between the distributor and furnace walls, each wall having an annular groove concentric with the axis of rotation, said grooves being opposed and facing each other in registered relation across the restricted gas escape path, and a sealing member seated in said opposed grooves and extending across said gap and blocking the restricted gas escape path.

2. The seal of claim 1 wherein each wall is provided with a plurality of grooves spaced along the restricted gas escape path and wherein the corresponding grooves in each wall are opposed and facing each other in registered relation, and a sealing member is seated in each of said spaced opposed grooves, said members operating progressively to block the restricted gas escape path.

3. A seal for preventing the escape of gas from between the top of a blast furnace and a distributor rotatably supported therein in horizontally spaced relation thereto to provide a clearance gap therebetween comprising, means forming a restricted gas escape path between the distributor and furnace walls, each wall having one or more annular grooves concentric with the axis of rotation and spaced along the restricted gas escape path, the corresponding grooves in each wall opposing and facing each other in registered relation across the restricted gas escape path, a sealing member seated in each of said spaced opposed grooves and extending across said gap and blocking the restricted gas escape path, and means for introducing a lubricant into the restricted gas escape path adjacent at least one of the sealing members.

4. A seal for preventing the escape of gas from between the top of a blast furnace and a distributor rotatably supported therein and having a gap therebetween comprising, means forming a restricted gas escape path between the distributor and furnace walls, each wall having an annular generally radially extending groove concentric with the axis of rotation, said grooves being opposed and facing each other in registered relation across the gas escape path, an annular sealing member seated in said opposed grooves and extending across said gap and blocking the gas escape path, and means for introducing and maintaining a column of a lubricating fluid in the gas escape path at the furnace side of said sealing member, whereby said furnace gas acts directly on said column of fluid in the gas escape path, and the fluid, in turn acts directly on the sealing member.

5. The seal of claim 4 wherein each of said walls is provided with a plurality of grooves spaced along the gas escape path and the corresponding grooves in each wall are opposed and facing each other in registered relation, and wherein the sealing member comprises coacting circular segments which are seated in each set of opposed grooves.

6. The seal of claim 4 wherein said means for forming a restricted labyrinth gas escape path includes a double radially spaced wall defining an annular trough around the top of the furnace and a double radially spaced wall carried by the distributor and defining an inverted annular trough encircling the distributor, said annular troughs being interleaved to form a restricted labyrinth path between the interior of the (furnace and the atmosphere when the distributor is assembled on the furnace top, and wherein said annular grooves are formed in the two outermost wall portions of the distributor and furnace respectively.

7. The seal of claim 4 wherein the portion of the furnace wall having the annular groove includes a plurality of annular wall segments assembled together in end to end relation to form a spider around the furnace top, and wherein said sealing member includes a plurality of annular segments having interlocking extremities assem bled together in end to end relation in the annular groove, whereby the annular segments are individually accessible without dismantling the entire wall spider.

8. In a seal for a blast furnace having an open top with spaced inner and outer concentric walls defining an annular trough closed at the bottom and open at the top and a distributor including a cylindrical charging hopper having a closure and rotatably supported within the furnace top, a depending sleeve encircling and carried by the hopper and adapted to extend into the annular trough at the top of the furnace to form a restricted labyrinth gas escape path from the interior of the furnace, the internal surface of said sleeve and the internal surface of said outer furnace wall each having an annular groove concentric therewith, said grooves being opposed and facing each other in registered relation across the restricted gas escape path, an annular sealing member of rubber-like material seated in said opposed grooves and blocking the gas escape path, and means for introducing and maintaining a column of a lubricating fluid in the gas escape path on the furnace side of said sealing member.

9. The apparatus of claim 8 wherein the external surface of said sleeve and the internal surface of said outer furnace wall are each provided with a plurality of annular grooves spaced along the gas escape path therebetween and the corresponding grooves in each wall surface are opposed and facing each other in registered relation across the gas escape path, and wherein an annular sealing member is seated in each set of opposed grooves and blocking the gas escape path.

10. The apparatus of claim 9 wherein said last-mentioned means separately introduces the fluid into the gas escape path between the spaced sealing members and at the furnace side of the sealing members.

References Cited in the file of this patent UNITED STATES PATENTS 

